Four Horsemen

A Horseman is a powerful and unique daemon, of which there are are four known, though there are rumors of a fifth. They rule Abaddon and have hordes of daemons in their service. Not all daemons are in the service of a Horseman, but many are.

The Four Horsemen are such powerful fiends that they are capable of granting spells and power to their deluded, nihilistic clerics. They do not have churches or organised faiths on the Material Plane, but rather are worshipped out of fear or by hate-filled monsters.[1]